回撤通道末采围岩稳定性分析与控制技术研究

Study on Stability Analysis and Control Technology of Surrounding Rock in the Final Mining of Withdrawal Roadway

针对工作面末采期间回撤通道矿压显现剧烈的问题,通过现场监测、数值模拟,研究了塔拉壕煤矿3101工作面回撤通道区域应力演化规律及围岩塑性破坏特征,结果表明:(1)在末采期间,工作面超前回撤通道20 m范围内影响剧烈,围岩失稳严重;(2)在工作面距主回撤通道20 m到贯通期间,主回撤通道区域应力分布从"非对称双峰值"状态逐步加强,最终演化为"对称单峰"状态,辅回撤通道区域应力场数值增加,状态基本不变;(3)末采期间,主回撤通道围岩塑性区逐步扩展,辅回撤通道围岩塑性区变化不明显。因此,基于顶帮协同控制的原则,提出预防性的主回撤通道补强支护方案,并配合末采期间围岩稳定性控制措施,现场应用效果良好。

Aiming at the problem of the severe strata behaviour in the withdrawal roadway during the final mining period, through on-site monitoring and numerical simulation, the regional stress evolution law and surrounding rock plastic failure characteristics of the 3101 working face in Talahao Coal Mine were studied. The results are concluded as follows.(1) During the final mining period, the influence of the working face within 20 m of the advance withdrawal roadway is severe, and the surrounding rock is seriously unstable.(2) During the period from 20 m to the penetration of the working face from the main withdrawal roadway, the stress distribution in the main withdrawal roadway changes from asymmetric double peak state gradually being strengthened and finally evolved into a symmetrical single peak state. The value of the stress field in the auxiliary withdrawal roadway area increases, and the state remains basically unchanged.(3) During the final mining period, the plastic zone of surrounding rock of the main withdrawal roadway gradually expands, and that of the auxiliary withdrawal roadway does not change significantly. Therefore, according to the principle of top-side collaborative control, and a preventive reinforcement support plan was proposed, coordinating with the surrounding rock stability control measures during the final mining period, has a good the field application effect.